Road join



Aug. 19, 1941. J.YH. JACOBSON ROAD JO INT Original Filed Jan. 10, 1954 2 Sheets-Sheet l Aug. 19 J. H; JAcoBsoN ROAD JOINT Original Filed m. 1011934 2v Sheets-Shem. 2

.Reissued Aug. 19, 1941 Re. 21,880 v :ROAD JOINS.

James H. Jacobson, Evanston, IlL, assignor to Gal 0. Chambers and Robert S. Bradshaw, Jr., St. Louis, Mo., as joint tenants Original No. 2,138,817, dated December 6, 1938, Serial No. 706,081, January 10, 1934. Application for reissue May 17,}940, Serial No. 335,834

21 Claims.

This invention relates to a method of transmitting road loads from an initially loaded slab or section of a roadway or the like to an adjacent slab or section.

The object of this invention is to provide means for transmitting/road load crosswise or trans versely of the slab sections and/or longitudinally or in the'line of travel of the roadway; and

To provide for transmitting road loads applied to one slab section to an adjacent slab section through the agency of an element which may provide part of a joint and seal between the slab sections; and

To confine the free flexing or bending of the dowel bars embedded in the material of the roadway to the space between slab sections of the roadway and to prevent or reduce the bending or flexing of that portion of the bar which extends from that space into the slab section in order to thereby reduce disintegration of the material of the slab due to the action of the bars upon said material because of the road load applied to the bar; and v .To accomplish the last mentioned advantage through a means extending crosswise or longitudinally of said roadway and arranged at a face or an end of a slab; and

To provide means for forming a support for an end of a slab section and the employment of this means to assist in accomplishing the prevention of the disintegrating action between the dowel and the material of the slab due to road load applied to the bar; and

To provide means for forming a support for an end of a slab and a bond between the. Joint and slab, this means assisting to transmit road loads from one slab section to an adjacent section; and v To provide means for sealing the space between the slab sections against the entrance of for- Qeign material permanently allowing for the free and independent lateral movement of the slab sections occasioned by road load, moisture, temperature change or subgrade displacement; this means accomplishing the above mentioned transmission of road loads from one slab section to it-another; and

' addition to sealing the space between said roadway sections, it is arrobject to employ the joint-as a means of support for dowel bars emj-ployed in the roadway structure and thus limit the-flexing of said bars and reduce the crushing action ofsaid bars on the slab and the resultant coning of the material of the slab surroundin the ba rsfdue to the road load being appliedto the complishing the invention, it being understood The invention has these and other objects, all of which will be explained in detail and more readily understood when read in conjunction with the accompanying drawings (two sheets) which illustrate various meansand the method of acthat other arrangements may be resorted to without departing from the spirit of the appended claims forming a part hereof.

In the drawings:

Fig. l is a perspective view of a joint embodying the invention; r

Fig. 2 is a'vertical section through Fig, 1;

Fig. 3 is an isometric view of the facing angles only, spaced apart but in their relative positions; and

Fig. 4 is a plan of the base of the joint, the top of the vertical angles being cut away and the seal removed, to show the bearing on the subgrade and the transverse load distribution or beam action of the angles.

Road building has passed through many phase in practice and design. The modern road or highway of today is considered and dealt with as a structure, not just a ribbon of concrete. The new structures as now designed bring with them the elements of greater cost and greater permanency; preservation of investment; a definite salvage value; and the economic and safe handling of agreatly increased volume, weight and speed of traflic.

an objective of highway design as are utility and safety.

A broad characteristic of the modern highway is the adoption of concrete for concrete pavement,

and/or for the bases of brick and bituminous surfaces, andthe provision of means providing for load distribution across the slab (transversely of the road) at this point; andthe specific inclusion of means for permanently sealing this joint against the entrance of foreign matter allowing of the free and independent movement of the slab occasioned by load, moisture, temperature change or subgracle displacement.

"My invention relates to design procedure as particularly applied to roadways involving the edges of the divided slab and develops critical stresses in a pavement that otherwise would be Appearance is also as definitely ment, but the selection of bars as to length, cross section and spacing has been largely a matter of judgment; and

Usually in computing the length of dowels, the dowels are figured for equal capacity in bending and bearing, without any allowance for contact with, or support from, any transverse steel. Increasing the length of a dowel beyond certain limits, increases its load carrying capacity in bearing, but reduces its capacity in bending.

It has been found with respect to load distribution and when a support is provided for the dowel bar at the top and bottom thereof, that this support increases the load carrying capacity of the dowel in bearing, particularly if the support is placed near the edge of the slab where the bearing pressure is greatest, this arrangement of support above and below the dowel bar being preferable becauseof reversal of load application under moving load.

The slab assumed to be subjected to the moving wheel load is herein referred to as the initially loaded slab, and the adjacent unloaded slab is defined as the opposite slab. Each slab edge abutting the transverse joint is denoted as the face of the slab.

A mechanical device for sealing the space between adjacent ends of the slab sections and providing means for accomplishing the distribution of road loads contemplates the utilization of a pair of angle members, designated I and II. The lateral flanges or feet of said angles are respectively designated l2 and I3, which feet engage the under side of said slab sections.

The vertical legs of the angles Ill and H, are spaced from each other to provide for movement of the angles l0 and II and thus compensate for the lateral movement of the slab sections. These .angles I 0 and II are. in the present instance partially held in spaced relation to each other through the agency of flex: ible spacers H at or near the base thereof. The upper end of the joint formed by the angles Ill and II is closed by a metallic seal l5, having the lateral flanges l6 and I1 which are adapted to be embedded in the aggregate forming the roadway. This last mentioned element is also provided with a longitudinal crimped portion or rib It! to provide for the resultant compressive movement of the angle elementsupon the expansion of the roadway sections. A bituminous cap or seal I9, is "employed which forms a closure for the entire structure and is further utilized to assist in sealing the space between the respective roadway sections to prevent the infiltration of water, dirt, etc., into the space between the slab sections. This bituminous member extends lengthwise of the joint and is temapertures for the reception of dowels 22 which are introduced to couple the ends of the respective slab sections to each other and transmit defined road loads from one slab section to anporarily secured to the joint through the agency of the binders 20, which are passed through keys 2|. The keys 2| extend through apertures provided in therespective vertical legs of the angles other. Each of these dowels may be provided with a thimble 23 which'wlll allow for movement of the dowels upon the lateral movement of the slab sections, and the dowels may be welded to alternate legs of the angles as shown at 30.

The load transmitting action resulting from the utilization of this structure causes material reduction in the flexing or bending of the dowel bars which thus reduces the channeling or coning of the concrete in the adjacent ends of the slab sections. It is also believed evident that the bending arm of these dowel bars is shortened and the bearing increased which also reduces channeling or coning of the material of the slab and which will further tend to contime the free action of the dowel bars to the space between the angles I0 and l I. The lateral flanges or feet I2 and I 3 of the angles in and II also act to carry or distribute the load from the slabs to the vertical legs of the angles and thence to the dowel bars. The flanges or feet l2 and I3 and the vertical legs l0 and II of the angles further contribute to distribute the load transversely of the roadway, and in this manner will cause distribution of the load to the several dowel bars.

It will be noted that the sealing member HI is formed to provide a downwardly facing, longitudinal channel 24, which tends to prevent extrusion of this material above the slabsurfaces due to the lateral movement of the slab sections.

The specific structure illustrating the invention and comprising the two angular elements generally designated Ill and II, the lower portion of each of which is formed to provide longitudinally spaced feet respectively designated I2 and I3, also has longitudinally spaced cutout portions respectively designated 25 and 26. The cut-out portions of one foot are arranged opposite the foot of the other leg, and the foot pieces are designed to be arranged in the cutout portions. In this manner the road load applied to the dowel bars 22 is transmitted from the leg H) to the leg ll, and/or from the leg II to the leg l0.

The metallic seal I'5 employed is provided with lateral flanges I8 and H, which are formed as at 21 to cap the upper extremity of the walls respectively designated Ill and II, and is additionally formed to provide a bridge piece which extends across said walls. This bridge is provided with a. longitudinal, centrally disposed rib I8, which will compensate for the movement of the walls I0 and H as before described. One

of the walls of the rib. l8 also forms a portion From the foregoing explanation of the struc ture involved it is believed evident that a new and novel means is provided for transmitting road load as it is applied to one slab section and thence transferred to the other slab secaneso tion through the medium of a device forming a joint between the respective slab sections. It

is further believed manifest that the structure provides means for increasing the load carrying capacity of. the dowel in bearing, and thus limits and prevents to a degree, the free bending of the dowel within the slab section which will then prevent channeling or coning of the material of the roadway. at the joint due to road loads applied to the dowel.

Having thus described rny invention, what I claim as new and desire to cover by Letters Patent is:

1. An expansion joint for concrete roads and i being located in the space between the feet of the,

other member and said feet extending under and forming a bearing for the oppositely disposed member, and a member'penetrating said slab sections and extending across the space between said sections and having bearing in each of said walls of the stool.

. 2. In a joint for concrete roads and the like adapted to seal the space intervening between adjacent slab sections, means for distributing the applied load transversely of the slab and also, transmitting this load from one slab section to the next adjoining, said load transfer means consisting of a pair of spaced angles having upstanding legs which abut the ends of their respective slab sections, the angles facing each other and alternately the foot of one being cut out at intervals so that theremaining foot sec.- tion of the other extends beyond and under the leg of the oppositely spaced angle and across the space intervening between the slab sections and into functionally operative engagement with the underside of the oppositely disposed slab section,

thereby providing a bearing for the leg of the opgle for distribution to the foot of the opposite angle and further providing means offering resistance to the rotation of the slab ends about the joint as an axis. V

4. A bearing for dowel bars comprising a pair of spaced angles facing the ends of adjoining slab sections, the foot of each angle being cut out at intervals in stag ered relation,'the remaining foot sections alternately passing under and forming a bearing for the leg of the oppositely disposed angle, and a dowel bar spanning the space between the angles and having bearing in the leg of each facing angle so that a portion of the applied load is distributed transversely of the slab on the facing angle and then carried across the space intervening between the facing angles and distributed to the feet of the angles both at the heel and at a point intermediate the toe and heel thereof, thereby accomplishing the distribution of the load to the feet of the angles and across the space intervening between the spaced facing angles.

5. A bearing for dowel bars comprising a pair of spaced facing angles, the foot of each angle being cut out at intervals, the remaining foot section passing under and forming a bearing for the leg of the oppositely disposed angle, and a dowel bar spanning the space between and having bearing in the leg of each facing angle, so that a portion of the applied load is distributed along the leg of the angle and then carried across the'space intervening between the facing angles and distributed by the leg of one angle to th feet of the opposed angle, the feet of each angle being reinforced against cantilever action by the leg of the opposing angle.

6. In a joint for concrete roads and the like adapted to seal the space intervening between adjacent slab sections, means for distributingithe applied load transversely of the slab and then transmitting the applied load from one slab section to the next adjoining, said means consisting of a pair of facing angles extending substantially the length of the joint the upstanding legs of each angle abutting the ends of their respective slab sections, a seal extending across the upper ,ends of said upstanding legs, the legs of posite angle, and a plurality of dowel bars spaced across the joint and engaging the adjacent slab sections and extending across the space' therebetween, said dowel bars being aflixed to'one leg of the opposite angle, whereby a portion of the applied load is carried by the dowel bar into the leg of each angle and distributed to the foot of each angle at more than two points.

3. In a joint for concrete roads and the like adapted to seal the space intervening between adjacent slab sections, means for distributing the applied load transversely of the slab and then transmitting the applied load from one slab section to the next adjoining, said means consisting of a pair of facing angles extending substantially the length of the joint, the upstanding legs of each angle abutting the ends of their respective slab sections, the legs of each angle having a plurality of spaced feet extending therefrom toward the opposite angle and across the space between the slab sections, the leg of each angle providing abearing for the top of the foot of the oppositely spaced angle, and a dowel member engaging both slab sections and extending across the space therebetween, said dowel having a bearing in each of the upstanding legs of the facing angles, said dowel member transmitting a each angle having a plurality of spaced feet extending therefrom toward the opposite angle and across the space between the slab sections, the leg of each. angle providing a bearing for the top of the foot of the oppositely spaced angle, and a dowel engaging both slab sections and extending across the space therebetween, said dowel having a bearing in each of the upstanding legs of the facing angles, said dowel transmitting a portion of the applied load to the leg of each angle for distribution to the foot of the opposite angle and providing means offering resistance to the rotation .of the slab ends about the joint as an axis.

7. In a joint for concrete roads and the like adapted to seal the space intervening between adjacent slab sections, means for distributing the applied load transversely of the slab and then transmitting the applied load from one slab section to the next adjoining, said means consisting of a pair of facing angles extending substantially the length of the joint, the upstanding legs of each angle abutting the ends of their respective slab sections, a flexible metallic seal engaging and extending across the upper ends of said up- 1 standing legs, said seal having means adapted to be anchored in the respective slab sections, the

leg ofjeach angle having a plurality of spaced feet extending therefrom toward the opposite angle and across the space betweeen the slab sections, the leg of each angle providing a bearing for the top of the foot of the oppositely spaced angle and a dowel engaging both slab sections and extending across the space therebetween, said dowel having a bearing in each of the upstanding legs of the facing angles, said dowel transmitting a portion of the applied load to the leg of each angle for distribution to the foot of the opposite angle and further providing means offering resistance to the rotation of the slab ends about the joint as an axis.

8. In a joint for concrete roads and the like adapted to seal the space intervening between adjacent slab sections, means for distributing the applied load transversely of the slab and then transmitting the applied load from one slab section to the next adjoining, said means consisting of a pair of facing angles extending substantially the length of the joint theupstanding legs of each angle abutting the ends of their respective slab sections, a flexible metallic seal extending across the upper ends of said upstanding legs, said seal having means respectively providing members for anchoring said seal to the respective slab sections, and a bituminous filler arranged above said seal, the legs of each angle having a plurality of spaced feet extending therefrom toward the opposite angle and across the space between the slab sections, the leg of each angle providing a bearing for the top of the foot of the oppositely spaced angle, and a dowel engaging both slab sections and extending across the space therebetween, said dowel having a bearing in each of the upstanding legs of the facing angles, said dowel transmitting a portion of the applied load to the leg of each angle for distribution to the foot of the opposite angle and further providing means offering resistance to the rotation of the slab ends about the joint as an axis.

tially the length of the joint the upstanding legs of each angle abutting the ends of their respective slab sections, and a plurality of yieldable means locatedadjacent to both the upper and lower extremities of said upstanding legs to maintain the foot of the opposite angle and further pro- 9. In a joint for concrete roads and the like adapted to seal the space intervening between,

adjacent slab sections, means for distributing the applied load transversely of the slab and then transmitting the applied load from one slabsection to the next adjoining, said means consisting of a pair of facing angles extending substantially the length of the joint the upstanding legs of each angle abutting the ends of their respective slab sections, and yieldable means located between said upstanding legs to maintain said legs in spaced relation to each other during the pouring of the concrete slabs, the legs of each angle having a plurality of spaced feet extending therefrom toward the opposite angle and across the space between the slab sections, the lcgof each angle providing a bearing for the top ofthe foot of the oppositely spaced angle, and a member engaging both slab sections and extending across the space therebetween, said member having a bearing in each of the upstanding legs'of the facing angles, said member transmitting a portion of the applied load to the foot of the opposite angle and further providing means offering resistance to the rotation of the slab ends about the joint as an ax1s.

10. In a joint for concrete roads and the like adapted to seal the space intervening between adjacent slab sections, means for distributing the viding means offering resistance to the rotation of the slab ends about the joint as an axis.

11. In 'a joint of the character described for concrete structures, a stiff structural girder, and dowels or anchor elements rigidly and permanently secured thereto and projecting laterally therefrom and adapted to project into and move. within an adjacent concrete section, during contraction and expansion of said section.

12. In a joint of the character described for concrete structures, a stiff structural girder,

dowels or anchor elements rigidly and permanently secured thereto and projecting laterally therefrom and adapted to project into and move within an adjacent concrete section, during contraction and expansion of said section, and laterally compressible means co-operating with said girder and disposed in a space between the proximate faces of adjacent concrete sections.

13. In a joint of the character described for concrete structures, a stiff structural girder, dowels or anchor elements rigidly and permanently secured thereto and projecting laterally therefrom and adapted to project into and move within an adjacent concrete section, during contraction and expansion of said section, and laterally compressible means co-operating with said girder, disposed within and closing a space between the proximate faces of adjacent concrete sections.

14. In a joint of the character described'for concrete structures, a stiff structural girder,

anchoring dowels rigidly and permanently secured thereto and projecting laterally therefrom and adapted to project into and move within an adjacent concrete section during contraction and 15.'In a joint of the character described for concrete structures, a stiff structural girder, an-

choring dowels rigidly and permanently secured thereto and projecting laterally therefrom and adapted'to project into and move within an adjacent concrete section during contraction and applied load transversely of the slab and then transmitting the applied load from one slab section to the next adjoining, said means consisting of a pair of facing angles extending substanexpansion, said sections being spaced, and a flexible substantially U shaped'element within and adjacent the bottom of the space between said sections,

16. In a joint of the character described for concrete structures, a stiff structural girder, an-

choring dowels rigidly and permanently secured thereto and projecting laterally therefrom and adapted to project into and move within an adjacent concrete section during contraction and expansion, said sections being sp'aced, a flexible ele'ment" extending across the top of the space between said sections to form a closure therefor, and 'a flexible element forming a. closure for the bottom of said space.

1'1. A bearing for dowel bars comprising a pair of spaced facing angles, each having a vertically disposed leg terminating in an angularly disposed foot, the foot of each angle passing under and forming a bearing for a portion of the leg of the companion angle, and a dowel bar for spanning the space between and having bearing in the leg of each facing angle so that load applied to either angle is distributed through the foot of the opposing angle, and wherein the foot of each angle is reinforced against cantilever action by the leg of the opposing angle.

18. A load transfer device for use in association with adjoining concrete slabs comprising a pair of spaced facing angle shaped members each having a vertically disposed leg anchored to the related slab and terminating in an angularly disposed foot, the feet of the respective angle shaped members extending oppositely and spanning the gap between the adjoining slabs and each foot passing under and forming a bearing for a portion of the leg of the oppositely disposed, angle shaped member so that a portion of the load applied to either leg is imparted to the foot of the opposite angle shaped member, and means for anchoring each angle shaped member to its related slab.

19. A device of the character described for bridging the joint gap between road slabs, comprising a pair of opposing spaced angles facing one another and each having a vertically disposed leg adapted to engage the joint face of an associated road slab and each leg provided at a relatively low level with an angularly disposed foot of less width than the length of the connected leg, the oppositely extending feet lying in staggered relation to one another and each foot passing beyond and forming a bearing for a portion of the leg of the companion angle, andmeans engaging the legs at a relatively high level for spanning the gap between the legs and extending in each direction therebeyond in position to enter through the joint faces and into the bodies of the road slabs, so that load applied to either angle is distributed through the foot of the opposing angle.

20. A device of the character described for bridging the joint gap between road slabs, comprising a pair of opposing spaced angles formed of plate material facing one another and each having a, vertically disposed leg adapted to engage flatwise against the joint face of an associated road slab and each leg provided at its base with an angularly disposed foot of less width than the length of the connected leg. the oppositely extending feet lying in staggered relation to one another and each foot passing under and beyond and forming a bearing for a portion of the leg of the companion angle, and means engaging the legs at a substantial distance above the feet for spanning the gap between the legs and extending in each direction therebeyond in position to enter through the joint faces into the bodies of the road slabs, so that load applied to either angle is distributed through the foot of the opposing angle.

21. A device of the character described for bridging the joint gap between road slabs, comprising a pair of opposing spaced angles facing one another and each having a vertically disposed ,leg adapted to engage the joint face of an associated road slab and each leg provided at a relatively low level with an angularly disposed foot so configured as to expose aportion of the connected leg to afford a contact surface for the foot of the opposed angle, the oppositely extend- I ing feet lying in staggered relation to one another and each foot passing beyond and forming a bearing for the contact portionof the leg of vthe companion angle, and means engaging the legs at a relatively high level for spanning the gap between the legs and extending in each direction therebeyond in position to enter through the joint faces and into the bodies ofthe load slabs, so that load applied to either angle is distributed through the foot of the opposing angle. 4 4 JAMES H. JACOBSON. 

